#include "apue.h"
#include <sys/times.h>

static void pr_times(clock_t, struct tms *, struct tms *);
static void do_cmd(char *);

int main(int argc, char *argv[]) {
    setbuf(stdout, NULL);
    for (int i = 1; i < argc; ++i) {
        do_cmd(argv[i]);
    }
    return 0;
}

/* execute and time the "cmd"*/
static void do_cmd(char *cmd) {
    struct tms tmsstart, tmsend;
    clock_t    start, end;
    int status;

    printf("\nocommand: %s\n", cmd);

    if ((start = time(&tmsstart)) == -1) {
        err_sys("times error");
    }
    if ((status = system(cmd)) < 0) {
        err_sys("system() error");
    }
    if ((end = times(&tmsend)) == -1) {
        err_sys("times error");
    }

    pr_times(end - start, &tmsstart, &tmsend);
    pr_exit(status);
}

static void pr_times(clock_t real, struct tms *tmsstart, struct tms *tmsend) {
    static long clktck = 0;

    if (clktck == 0) {
        if ((clktck = sysconf(_SC_CLK_TCK)) < 0) {
            err_sys("sysconf error");
        }
    }
    printf(" real:        %7.2f\n", real / (double)clktck);
    printf(" user:        %7.2f\n",
        (tmsend->tms_utime - tmsstart->tms_utime) / (double)clktck);
    printf(" sys:         %7.2f\n",
        (tmsend->tms_stime - tmsstart->tms_stime) / (double)clktck);
    printf(" child user:  %7.2f\n",
        (tmsend->tms_cutime - tmsstart->tms_cutime) / (double)clktck);
    printf(" child sys:   %7.2f\n",
        (tmsend->tms_cstime - tmsstart->tms_cstime) / (double)clktck);
}